As the beginning of manufacturing, all components must be marked to improve the monitorability of the material. Due to the corresponding number of components, marking can be performed. In addition, all dimensions of the piping spools must be marked on it. The traces on the components must not contaminate the material, otherwise the traces will react with the material, which may cause harmful problems.
The following steps after marking are cutting steps. Different materials have different cutting methods. Therefore, for carbon steel, flame cutting method is adopted. In addition, a plasma arc cutting machine can be used to cut stainless steel parts. If a plasma arc cutting machine is used, certain conditions must be maintained. The plasma arc cutting machine is used for large pipes (the nominal pipe size exceeds 28 inches), and its use is also conducive to cutting off branches. If possible, an internal enclosure must be placed in the pipe or fitting to protect them from splashes generated by the plasma arc cutting machine. After cutting, the edges must be kept ready. The surface edge of the part must be flat, and the surface impurities must be removed. Bevel the edge of the part. Use a grinder for bevel processing. The types of bevel grinders for stainless steel parts and carbon steel parts are different.
After the edge of the part is completed, assembly and welding processes must be applied. Therefore, for stainless steel and carbon steel piping spools, the parts can be located on a steel base or a wooden base. In addition, any possibility of contact between carbon steel and stainless steel must be minimized. The number of welds on the spool must be kept to a minimum. The distance between the circumferential weld and the center line shall not be greater than four times the wall thickness of the pipe or pipe fitting. After the main weld, tack welding must be accurately performed. All welds in the spool must be made in accordance with the correct welding procedure specification (WPS). After the welding process is completed, the quality control of the components is carried out by experts.